Rock drill supporting device for controlling the drilling direction

ABSTRACT

A supporting device for a rock drill where the rock drill is mounted slidably on a guide cell supported rotatably at the top of a boom mounted swingably on a base. The boom forms a parallel link mechanism with a link disposed in parallel with the boom, whereby the guide cell moves in response to swinging of the boom while being maintained in parallel with the boom. At least one of two opposing latera interconnecting the boom and the link of the parallel link mechanism is variable in length. The guide cell inclines in response to swinging of the boom when the length of the latus on the top side of the boom is made longer than that of the other latus on the base side.

United States Patent 1 Kawano ROCK DRILL SUPPORTING DEVICE FOR CONTROLLING THE DRILLING DIRECTION Inventor:

Toru Kawano, I-Iiroshima-shi, Japan Assignee: Toyo Kogyo Company, Ltd.,

Hiroshima, Japan Filed: Aug. 5, 1971 Appl. No.: 169,446

[30] Foreign Application Priority Data Aug. 5, 1970 Japan 45/7838] Mar. 31, 1971 Japan 46/23953 U.S. Cl. 243/2, 173/43 Int. Cl. E210 9/00 Field of Search 248/2, 16, 281;

References Cited FOREIGN PATENTS 0R APPLICATIONS Switzerland 173/43 Primary Examiner-J. Franklin Foss Attorney-Richard C. Sughrue et a].

[57] ABSTRACT A supporting device for a rock drill where the rock drill is mounted slidably on a guide cell supported rotatably at the top of a boom mounted swingably on a base. The boom forms a parallel link mechanism with a link disposed in parallel with the boom, whereby the guide cell moves in response to swinging of the boom while being maintained in parallel with the boom. At least one of two opposing latera interconnecting the boom and the link of the parallel link mechanism is variable in length; The guide cell inclines in response to swinging of the boom when the length of the latus on the top side of the boom is made longer than that of the other latus on the base side.

12 Claims, 5 Drawing Figures ROCK DRILL SUPPORTING DEVICE FOR CONTROLLING THE DRILLING DIRECTION BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supporting device of a rock drill for controlling the drilling direction of the rock drill mounted slidably on a guide cell in accordance with the rotation angle of a boom, and, more particularly, to the supporting device which produces a trajectory that permits an automatic drilling operation in any radial direction of a tunnel.

2. Description of the Prior Art One of the most significant problems encountered in cutting tunnels in the course of mine constructions is excessive cutting due to back break (i.e., a rock tends to be broken beyond an intended break line). Recently, a Smooth Blasting Method has been proposed as a countermeasure against excessive cutting. This Smooth Blasting Method is characterized in that it directs the energy generated by an explosion only to areas where rock destruction is desired and prevents that energy from influencing other areas where destruction is not desired. That is, this method is a blasting technique aiming at creating as precisely as possible a flat plane of blasting at a given blasting line of a tunnel.

In cutting a tunnel, it is desirable that holes in the tunnel wall drilled by a rock drill be extended horizon tally; but, as the result of the drilling property of the rock drill, a gallery becomes small in diameter as it advances forward. Accordingly, the drilling direction of the rock drill tends to incline from the horizontal direction to take the radial directions of the tunnel. Thus, it is a common practice to solve the foregoing problem to incline a guide cell supporting the rock drill in the radial directions of the tunnel.

However, according to the conventional boom jambo technique, ladder technique and the like, the operation to drill precisely in a given direction at a given location is very complex and hardly possible. Whether the Smooth Blasting Method can be practiced accurately or not depends first on the precision of the drilling technique since the drilling technique influences the final results. Byuse of the conventional rock drill of the prior art it was extremely difficult if not impossible to perform a drilling operation precisely ata given location in a given direction. Therefore, the advantages of the epoch-making technique called Smooth Blasting Method could not be fully realized.

It is an object of the present invention to provide a supporting device for a rock drillby which drilling at a selected location in a given direction can be effected through a simple manipulation of the swing of the boom.

It is another object of the present invention to provide a supporting device for arock drill having a parallel drive boom in which two opposite latera connecting a boom and a link of thesame length are differentiated in length so that the drilling direction of the rock drill inclines, as the boom inclines, in the inclined direction of the boom.

It is another object of the present invention to provide a supporting device for a rock drill having aparallel drive boom in which at least one of two opposite latera connecting a boom and a link of the same length can be varied in length so that one latus on the side where the rock drill is mounted becomes longer than that of the other latus.

It is another object of the present invention to provide a supporting device for a rock drill of the above type which can control the degree of inclination of the drilling direction of the rock drill in accordance with the inclination of the boom by varying the length of at least one of the two opposite latera.

It is another object of the present invention to provide a supporting device for a rock drill of the above type in which the boom and the link are bent at an appropriate angle about a point where the trajectory depicted by the rear end portion of the guide cell when it moves in response to swinging of the boom intersects with the boom.

SUMMARY OF THE INVENTION According to the present invention, there is provided a supporting device for a rock drill which has a parallel link mechanism comprising a boom and at least one link, and is characterized by the fact that at least one BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing an embodiment of the present invention;

FIG. 2 is an elevational side view of the device shown in FIG. 1;

FIG. 3 is a perspective view showing the connection arrangement of Portion A indicated in FIG. 1;

FIGQ4 is a perspective view showing the connection arrangement of Portion B indicated in FIG. 1; and

FIG. 5 is a plan view of another embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, a frame 2 is connected through an axle 3 to the front surface of a base body 1, which may be secured to a jambo and the like, to pivot leftward and rightward in relation to the base body (upward and downward as viewed in FIG. 1). A root portion of a boom 4 is connected through an axle 5 to the frame 2 to allow the boom to pivot upward and downward (as viewed in FIG. 2). A boom swing cylinder 6 and a boom lift cylinder 7 coupled to the front surface of the base 1 function to pivot the boom .4 left and rightward and up and downward wherein they are connected to the boom 4 through their piston rods.

Links 8 and 9 are disposed, respectively, aside (underside in FIG. 1) and above (in FIG. 2) the boom 4 in parallel therewith, and have the same length as that of the boom. The root portions of the links 8 and 9 are, respectively, which in turn are connected through axles 10 and '11, respectively, to the front surface of the base 1 to pivot leftward and rightward (upward and downward as viewed in FIG. 1).

Specifically, the link 8 is connected through an axle 15 to the frame 12 to pivot upward and downward. A screw 16 inserted from the left or right into a bracket 14 is secured to the base 1 is rotatably supported thereby. A block 17 through which the screw 16 threads can move leftward and rightward (as viewed in FIG. 3) along guides 18 formed in the bracket 18 carries the axle 10.

The link 9 is connected at its root portion through an axle 22 to a block 21 which moves upward and downward (as viewed in FIG. 4) within the frame 13 by operation of a screw 20. The axle 22 moves upward and downward together with the block 21 while guided by elongated holes 23 formed in side walls of the frame 13. A nut 24 serves to keep the block 21 stationary when it is fitted about a threaded portion of the axle 22.

As seen in FIGS. 1 and 2, a frame shaft 25 is inserted horizontally into a frame 27 which is connected through an axle 26 to the top of the boom 4, the pointed end of the frame shaft 25 connects pivotably through an axle 30 to a mounting 29 for supporting a guide cell 28.

A rock drill 31 is mounted on the guide cell 28 and can slide thereon by means of a feed screw or chain driven by a motor 32. A connecting rod 33 has a length substantially equal to the distance between the axles 3 and 10, respectively, of the boom 4 and the link 8, the root portion of the connecting rod 33 is secured to the afore-mentioned frame 27, and its top is connected through an axle 34 to the link 8. A connecting rod 35 has a length substantially equal to the distance between the axles 5 and 22, respectively, of the boom 4 and the link 9, its root portion is secured to the frame shaft 25, and its top is connected through an axle 37 to a frame 36 of a given length to allow free up and down pivotal movement of the frame 36. The top of the frame 36 is connected through an axle 38 to the top of the link 9 to allow free leftward and rightward pivotal movement of the link 9. The axles 38 and 26 are arranged so that the center of axle 38 coincides with the center of axle 26 of the frame 27 connected to the top of the boom 4.

In order to facilitate an understanding of the present invention, in FIG. 1, points a and b are the rotation centers, respectively, of the axles 3 and 26 at the ends of the boom 4 and points and d are the rotation centers, respectively, of the axles 10 and 34 at the ends of the link 8. Then, under the condition that (Yb FT and E 51?, the guide cell 28 can move in parallel in response to any swinging of the boom 4.

If the screw 16 is adjusted so that the axle 10 of the link 8 is shifted toward the boom 4 (see FIG. 3), the condition that 55 Eli and a 'c 53 can be obtained under the state that the boom 4 and the guide cell 28 are almost in parallel with one anotherl In the above state, if the boom 4 is pivoted about the axle 3 leftward or rightward, the greater the boom 4 swings, the farther outward the guide cell 28 swings.

Similarly, in FIG. 2, points e and are defined as the rotation centers, respectively, of the axles and 25 at the ends of the boom 4 and the points 8 and h are the rotation centers, respectively, of axles 22 and 37 at the ends 2f the link 9. Under the condition that eT=g h and eg flu the guide cell can move in parallel in response to any swinging of the boom 4. If the screw 20 is adjusted so that the axle 22 of thelinkg is shifted to ward the boom 4, the condition that ef= gh and eg flu can be obtained under the state that the boom 4 and the guide cell 28 are almost parallel with one another. In the above state, if the boom 4 is pivoted about the axle 5 upward or downward, the greater the boom 4 swings the farther outward the guide cell 28 swings.

As noted above, according to the invention, the links 8 and 9 can be shifted relative to the boom 4 through adjustment of the screws, so that the device can be simply controlled and the precise setting of the angle of elevation of the guide cell can be smoothly and quickly performed. Further, it is possible to drill desired radial holes only through operation of the boom lift cylinder 7 and the boom swing cylinder 6.

In the afore-mentioned arrangement, since the guide cell can interfere with the boom when the boom turns a large number of degrees, the drillable working range may be limited somewhat. That is, in cases where the guide cell 28 is disposed in parallel with the boom 4, and if the boom 4 and the guide cell 28 are the same height, the rear end portion of the guide cell 28 can interfere with the boom 4 when the boom 4 pivots laterally (vertically as viewed in FIG. 1). Thus, even though there is a space between the wall surface of a tunnel and the link, it would be impossible to completely turn the boom and the drillable working range is limited accordingly.

To overcome the above drawback, the boom 4 can be bent, as shown in FIG. 5, at an appropriate angle about the point where the trajectory depicted by the rear end portion of the guide cell when the boom 4 pivots intersects with the boom 4. By this modification, any interference between the guide cell and the boom can be prevented, and a sufficient working range and efficient drilling operation of the device can be obtained.

Although there has been described hereinabove the preferred embodiment, various modifications may be accomplished within the present invention.

In the afore-mentioned embodiment, the distance be tween the boom and the link on the base side was regulated. However, it should be noted that the length of the connecting rod on the boom top side can also be regulated to provide the same function as the above arrangement. v

Further, it is possible to obtain anincreased-degree of inclination of the guide cell by controlling the distances between the boom and the link on both ends. Though in the embodiment the screw adjusting means was used to vary the distance on the base side, it is also possible to incorporate cylinder means in the connecting rod and to control the length thereof. by means of air or oil pressure.

Furthermore, it is possible to provide an elongated groove or projection for sliding on the base, to provide slide means at the root portion of the link as to couple slidably with the groove or projection, and to use ap-v propriate fixing means to secure the link to the base.

Still further, in case it is desirable to provide a large change in the drilling direction of the rock drill, it may be sufficient to provide a cylinder 39 in the link to vary the links length, as shown inFIG. 2.

What is claimed is: j

1. A support device for a rock drill mounted on a guide cell comprising a base member; a boom pivotably mounted on the base member; means for'moving the boom; a first and second link member positioned adjacent and parallel to the boom; first connecting means for connecting the first and second links adjacent the free end of the boom and connected to the guide cell; second connecting means for connecting the first and second links with the boom adjacent the base member, the boom and each of the first and second links forming together a respective quadrilateral, means for varying the length of at least one of the first and second connecting means to vary the distance between the ends of one of the links and the boom, wherein when the first and second connecting means are the same length the guide cell will move parallel to the boom as the boom pivots about the base member and when at least one of the first and second connecting means is varied in length relative to the other the drilling position of the rock drill will vary in response to the swinging of the boom about the base member.

2. A support device as in claim 1, where the first and second link are the same length as the boom and are mounted 90 apart relative to the boom position.

3. A supporting device for a rock drill as specified in claim 2, wherein said means for varying the length of at least one of the connecting means includes a screw adjusting means for controlling its length.

i 4. A supporting device for a rock drill as specified in claim 2, wherein the second link includes a slide means for controlling its length.

5. A supporting device for a rock drill as specified in claim2, wherein at least one of said first and second links has a control cylinder for varying the drilling direction.

'6. A supporting device for a rock drill as specified in claim 3, wherein the screw adjusting means are secured to the base member, the screw adjusting means including a block which moves in response to rotation of the screw, the first and second links are connected with the block so that they shift with respect to the boom in response to rotation of the screw, and are connected pivotably through the block to the base member.

7. A support device for a rock drill mounted on a guide cell comprising a base member; a boom pivotably mounted on the base member; means for moving the boom; a first and second link member positioned adjacent to the boom; first connecting means for connecting the first and second links adjacent the free end of the boom and connected to the guide cell; second connecting means for connecting the first and second links with the boom adjacent the base member, means for varying the length of at least one of the first and second connecting means to vary the distance between one of the links and the boom, wherein when the first and second connecting means are the same length the guide cell will move parallel to the boom as the boom pivots about the base member and when at least one of the first and second connecting means is varied in length relative to the other the drilling position of the rock drill will vary in response to the swinging of the boom about the base member, the boom and the first and second links being inclined relative to the base member at a point where the trajectory depicted by the rearmost portion of the guide cell intersects with the plane of the boom when the guide cell moves in response to the motion of the boom. 

1. A support device for a rock drill mounted on a guide cell comprising a base member; a boom pivotably mounted on the base member; means for moving the boom; first and second link members positioned adjacent to the boom and being the same length as the boom; first connecting means for pivotably connecting the free end of the boom with respective free ends of the first and second link members adjacent the free end of the boom and mounting the guide cell; second connecting means for pivotably connecting another end of the boom with other ends of the first and second link members adjacent the base member, and fixed to the base member, the boom and each of the first and second link members forming respective quadrilaterals together with the first and second connection means, means for varying the length of at least one of the first and second connecting means to vary the distance between the ends of one of the link members and the boom from the state that the length of the first connecting means is longer than that of the second connecting means to the state that the length of the first connecting means is the same as that of the second connecting means, the boom being the same length as the first and second link members, wherein when the first and second connecting means are the same length the guide cell will move in parallel as the boom pivots about the base member and will maintain a constant drilling direction and when at least one of the first and second connecting means is varied in length relative to the other within the state that the first connecting mEans is longer than the second connecting means the drilling position and the drilling direction of the rock drill will vary in response to the swinging of the boom about the base member.
 2. A support device as in claim 1, where the first and second link are the same length as the boom and are mounted 90* apart relative to the boom position.
 3. A supporting device for a rock drill as specified in claim 2, wherein said means for varying the length of at least one of the connecting means includes a screw adjusting means for controlling its length.
 4. A supporting device for a rock drill as specified in claim 2, wherein at least one of the first and second connecting means includes a slide means for controlling its length.
 5. A supporting device for a rock drill as specified in claim 2, wherein at least one of said first and second links has a control cylinder for varying the drilling direction.
 6. A supporting device for a rock drill as specified in claim 3, wherein the screw adjusting means are secured to the base member, the screw adjusting means including a block which moves in response to rotation of the screw, the first and second links are connected with the block so that they shift with respect to the boom in response to rotation of the screw, and are connected pivotably through the block to the base member.
 7. A support device for a rock drill mounted on a guide cell comprising a base member; a boom pivotably mounted on the base member; means for moving the boom; a first and second link member positioned adjacent to the boom; first connecting means for connecting the first and second links adjacent the free end of the boom and connected to the guide cell; second connecting means for connecting the first and second links with the boom adjacent the base member, means for varying the length of at least one of the first and second connecting means to vary the distance between one of the links and the boom, wherein when the first and second connecting means are the same length the guide cell will move parallel to the boom as the boom pivots about the base member and when at least one of the first and second connecting means is varied in length relative to the other the drilling position of the rock drill will vary in response to the swinging of the boom about the base member, the boom and the first and second links being inclined relative to the base member at a point where the trajectory depicted by the rearmost portion of the guide cell intersects with the plane of the boom when the guide cell moves in response to the motion of the boom.
 8. A support device as in claim 1, wherein said first and second link members are mounted 90* apart relative to the boom position.
 9. A support device for a rock drill as in claim 1, wherein the boom and the first and second link members are inclined relative to the base member at a point where the trajectory depicted by the rearmost position of the guide cell intersects with the plane of the boom when the guide cell moves in response to the motion of the boom.
 10. A support device for a rock drill mounted on a guide cell comprising a base member; a boom pivotably mounted on the base member; means for moving the boom; first and second link members positioned adjacent to the boom; first connecting means for pivotably connecting the free end of the boom with respective free ends of the first and second link members adjacent the free end of the boom and mounting the guide cell; second connecting means for pivotably connecting another end of the boom with other ends of the first and second link members adjacent the base member and fixed to the base member, the boom and each of the first and second link members forming respective quadrilaterals together with the first and second connecting means, means for varying the length of at least one of the first and second link members to vary the distance between the ends of the first connecting means and the second connecting means.
 11. A supPort device for a rock drill mounted on a guide cell comprising a base member; a boom pivotably mounted on the base member; means for moving the boom; first and second link members positioned adjacent to the boom and being the same length as the boom; first connecting means for pivotably connecting the free end of the boom with respective free ends of the first and second link members adjacent the free end of the boom and mounting the guide cell; second connecting means for pivotably connecting another end of the boom with other ends of the first and second link members adjacent the base member and fixed to the base member, the boom and each of the first and second link members forming respective quadrilaterals together with the first and second connecting means, the length of the first connecting means being longer than the length of the second connecting means.
 12. A support device as in claim 11, further comprising means for varying the length of at least one of the first and second connecting means to vary the distance between the ends of one of the first and second link members and the boom. 